Tissue treatment apparatus and systems with pain mitigation and methods for mitigating pain during tissue treatments

ABSTRACT

Methods, apparatus, and systems for delivering electromagnetic energy to a patient&#39;s tissue with a reduction in the pain experienced by the patient. Electromagnetic energy is delivered from a treatment electrode through the skin surface to the tissue at a plurality of power levels over a treatment time. During the energy delivery, a portion of the treatment electrode is in a contacting relationship with the skin surface. A dielectric member may be disposed between the treatment electrode and the skin surface when the electromagnetic energy is delivered.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims the benefit of application Ser. No. 61/143,537,filed Jan. 9, 2009 and claims the benefit of application Ser. No.61/226,138, filed Jul. 16, 2009, which are hereby incorporated byreference herein in their entirety.

BACKGROUND

The invention generally relates to apparatus, systems, and methods fortreating tissue with electromagnetic energy and, more particularly,relates to treatment apparatus, systems, and methods for mitigatingpatient pain while treating tissue with high frequency electromagneticenergy.

Various cosmetic tissue treatments use energy delivery devices tonon-invasively and non-ablatively treat tissue in order to improve apatient's appearance, such as smoothing and tightening skin; contouringalong the jaw line and under the chin, and improving skin texture;softening wrinkles around the mouth, eyes and forehead; reducingcellulite; or removing skin spots or hair. These non-invasive,transcutaneous procedures involve no surgery or injections but insteadproject electromagnetic energy into the tissue. Such non-invasive energydelivery devices may emit the electromagnetic energy in differentregions of the electromagnetic spectrum to accomplish the tissuetreatment with reduced patient recovery time in comparison with ablativeprocedures.

Skin is a type of body tissue that includes plural distinct layers. Theepidermis constitutes the visible outer layer on the surface. Thedermis, which underlies the epidermis, contains collagen fibers, bloodvessels, hair follicles, and other skin components. The hypodermis orsubcutaneous fat layer, which underlies the demis, consists of fattissue and a web of collagen fibers in the form of fibrous septaerunning through the fat. The fibrous septae secure the dermis to theunderlying bone and muscle. Collagen fibers are recognized to be a veryflexible and stretchable protein and are characterized by a high tensilestrength.

The occurrence of wrinkles is an unavoidable natural process. Wrinklesare primarily associated with advancing age and skin damage arising fromexposure to damaging environmental factors. Environmental factorsinclude sun damage from exposure to sunlight, air pollution, smoking,repetitive facial movements such as frowning, and the natural effects ofgravity, which cause sagging of the skin with advancing aging.Deteriorating collagen exhibits a loss of elasticity, which results inthe formation of rhytids or wrinkling of the epidermis.

Electromagnetic radiation, specifically light and heat, applied to thedifferent layers of the skin can have a physiological effect on theskin's appearance. In particular, electromagnetic energy can arrest theformation of wrinkles and impart a more youthful skin appearance. Highfrequency treatment devices, such as radio-frequency (RF)-basedtreatment devices, may be used to treat skin tissue non-ablatively andnon-invasively with heat. Such high frequency devices operate bytransmitting high frequency energy through the epidermis to theunderlying tissue, while actively cooling the epidermis to preventthermal damage to a depth of the skin tissue near the skin surface. Thehigh frequency energy heats the tissue at depths beneath the cooledregion to a therapeutic temperature sufficient to denature the collagen,which causes the collagen fibers in the dermis to shrink and contract.In addition to the tightening of the treated tissue as the collagenfibers contract, treatment with high frequency energy also causes a mildinflammation. The inflammatory response of the treated tissue may causenew collagen to be generated over time, which can result in additionaltissue contraction. When the inflammatory response of the treated tissueis highly significant, the new collagen formed is known as scarcollagen.

Conventional high frequency treatment devices employ a handpiece, adisposable treatment tip coupled with a nose of the handpiece, and ahigh frequency generator connected by conductors inside the handpiecewith an electrode in the treatment tip. Conventional electrodes consistof a pattern of one or more metallic features carried on a flexibleelectrically insulating substrate, such as a thin film of polyimide. Thesubstrate contacts the patient's skin surface during treatment and themetallic features reside on the non-contact side of the substrate. Thetemperature of the treatment tip, which is measured by temperaturesensors carried on the treatment tip, is correlated with the temperatureof the patient's skin During the procedure, the doctor controls theenergy density of the high frequency power delivered from the electrodewith a treatment setting. Treatment tips are frequently intended forsingle patient use and, therefore, are not reusable. Following thepatient treatment, the doctor or treatment technician removes thetreatment tip from the handpiece and, if disposable, discards it.

Patient pain is inherent in tissue treatments using electromagneticenergy. Patient pain is typically regulated to optimize the treatmentresult while also minimizing patient discomfort to make the proceduretolerable. A patient may be given an oral pain medication and/or a localtopical anesthesia cream may be applied as a numbing agent. At theinception of the treatment procedure, the doctor will initiallyadminister the high frequency energy at a treatment setting to one ormore test sites and monitor patient feedback on the heat sensationassociated with the treatment setting being used. A tolerable, yetcomfortable, treatment setting for the treatment procedure isestablished based upon the patient feedback from the test sites.

The treatment electrode used in the treatment includes a conductorregion delimited by an outer peripheral edge. For monopolar energydelivery, an edge effect has been observed at the outer peripheral edgethat causes the energy density of the high frequency energy delivered tothe tissue to be non-uniform across the surface area of the treatmentelectrode. Specifically, the energy density is highest near theperipheral edge of the electrode. As a result, tissue proximate to theouter peripheral edge of the electrode is heated to a higher temperaturethan tissue proximate to the interior surface area of the electrode. Thehigher temperatures near the peripheral edge form hot spot thermal zonesthat are a highly likely source of heat-related pain perceived by thepatient. Because patient discomfort is linked with the treatmentsetting, reducing the treatment level to counteract the edge effecteffectively reduces the average energy density for the high frequencyenergy delivered during the treatment procedure.

In general, treatment results and the chance for pain or discomfort willscale with the treatment setting used by the doctor. What is needed,therefore, are apparatus and methods for reducing the pain associatedwith such tissue treatments so that patient discomfort is alleviated andtherapeutic results can be improved by increasing the treatment settingand the amount of heat delivered to the skin.

SUMMARY OF THE INVENTION

Embodiments of the invention are generally directed to methods,apparatus, and systems for transcutaneously delivering electromagneticenergy to treat patient tissue underlying a skin surface, particularlyduring non-invasive and non-ablative therapeutic tissue treatments, withreduced patient pain.

In one embodiment, a method is provided for operating a tissue treatmentapparatus to transcutaneously treat tissue located beneath a skinsurface with electromagnetic energy delivered from a treatmentelectrode. The method includes contacting a portion of the treatmentelectrode with the skin surface and, while maintaining the contactbetween the portion of the treatment electrode and the skin surface,delivering the electromagnetic energy from the treatment electrodethrough the skin surface to the tissue at a plurality of differing powerlevels over a treatment time. Preferably, a magnitude of the power ateach of the power levels incrementally decreases with increasing (i.e.,accumulating) treatment time. The progressive change in the power leveloperates to reduce patient pain so that a greater amount of heatdelivered to the skin.

In another embodiment, a system is provided for transcutaneouslytreating tissue located beneath a skin surface with electromagneticenergy. The system includes a handpiece and a treatment tip coupled in aremovable manner with the handpiece. The treatment tip includes atreatment electrode having a portion configured to be placed in acontacting relationship with the skin surface. The treatment electrodeis configured to deliver the electromagnetic energy through the skinsurface to the tissue. The system further includes a generatorelectrically coupled with the treatment electrode and a controller inoperative connection with the generator. The generator is adapted toenergize the treatment electrode to deliver the electromagnetic energyfrom the treatment electrode to the tissue. The controller is configuredto deliver the electromagnetic energy from the treatment electrodethrough the skin surface to the tissue at a series of power levels overa treatment time while the portion of the treatment electrode is incontact with the skin surface.

In another embodiment, an apparatus is provided for a treatment tip usedin treating tissue located beneath a skin surface. The treatment tip hasa treatment electrode configured to deliver electromagnetic energytranscutaneously through the skin surface to the tissue. The apparatusincludes a sleeve, which is composed of an electrically-insulatingmaterial, coupled with the treatment tip. The sleeve includes a frameand an aperture in the frame that exposes a portion of the treatmentelectrode. The frame is disposed between the treatment electrode and theskin surface when the electromagnetic energy is transcutaneouslydelivered from the treatment electrode through the skin surface to thetissue.

In yet another embodiment, a method is provided for operating a tissuetreatment apparatus to transcutaneously treat tissue located beneath askin surface with electromagnetic energy delivered from a treatmentelectrode. The method includes contacting a portion of the treatmentelectrode with the skin surface and separating a different portion ofthe treatment electrode from the skin surface with a spacer. Whilemaintaining the contact between the portion of the treatment electrodeand the skin surface, the electromagnetic energy is transcutaneouslydelivered from the treatment electrode through the skin surface to thetissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a treatment system with a handpiece, atreatment tip, and a console in accordance with an embodiment of theinvention.

FIG. 2 is a diagrammatic view of a portion of the treatment system ofFIG. 1.

FIG. 3 is a rear view of the treatment electrode of FIG. 1.

FIG. 4 is a graphical view showing a power profile for use in operatingthe treatment system of FIGS. 1-3.

FIG. 5 is a partial perspective view of the handpiece and treatment tipof FIG. 1 in which an electrically-insulating sleeve in accordance withan embodiment of the invention is applied to the treatment tip.

FIG. 6 is a cross-sectional view of the treatment tip andelectrically-insulating sleeve of FIG. 5 during use.

FIGS. 7-9 are front views of electrically-insulating sleeves inaccordance with different alternative embodiments of the invention.

FIG. 10 is a partial perspective view of the handpiece and treatment tipto which is applied a tip frame composed of a dielectric material inaccordance with an alternative embodiment of the invention.

FIG. 11 is a partial perspective view of the handpiece and treatment tipto which is applied a tip frame composed of a dielectric material inaccordance with an alternative embodiment of the invention.

FIG. 11A is a front view of the tip frame of FIG. 11.

FIG. 12 is a cross-sectional view of the treatment tip and tip frame ofFIG. 11 during use.

DETAILED DESCRIPTION

With reference to FIGS. 1-3, a treatment apparatus 10 generally includesa handpiece 12, a treatment tip 14 coupled in a removable and releasablemanner with the handpiece 12, a console generally indicated by referencenumeral 16, and a system controller 18. The system controller 18, whichis incorporated into the console 16, orchestrates the global operationof the different individual components of the treatment apparatus 10.Under the control of the system controller 18 and any operatorinteraction with the system controller 18 at the console 16 and withcontrols at the handpiece 12, the treatment apparatus 10 is adapted tonon-invasively and non-ablatively deliver electromagnetic energy in ahigh frequency band of the electromagnetic spectrum, such as theradiofrequency (RF) band, to a region of a patient's tissue. Thedelivered energy heats the tissue to a targeted temperature range. Theelevation in temperature may produce for example, changes in collagenfibers that achieve a desired treatment result, such as removing orreducing wrinkles and otherwise tightening the skin to thereby improvethe appearance of a patient receiving the treatment. In alternativeembodiments, the treatment apparatus 10 may be configured to deliverenergy in the infrared band, microwave band, or another high frequencyband of the electromagnetic spectrum, rather than within the RF band, tothe patient's tissue.

The treatment tip 14 includes a housing 15 and a treatment electrode 20supported by the housing 15. The treatment electrode 20, which has aportion that directly contacts the skin surface, may assume therepresentative form of an electrically-insulating substrate 22 and aplurality of active electrodes 24, 26, 28, 30 carried on theelectrically-insulating substrate 22. Each of the active electrodes 24,26, 28, 30 can be individually powered to deliver electromagnetic energyto the tissue. The substrate 22 is composed of a non-conductivedielectric material and the active electrodes 24, 26, 28, 30 arecomposed of an electrical conductor. The active electrodes 24, 26, 28,30 are positioned on the substrate 22 such that one of the activeelectrodes 24, 26, 28, 30 is disposed in each of the four quadrants ofthe treatment electrode 20. The active electrodes 24, 26, 28, 30, whichare electrically isolated from each other and are composed of anelectrical conductor, may have identical surface areas or differentsurface areas. In one embodiment, each of the individual activeelectrodes 24, 26, 28, 30 has a surface area of about three mm². Insideedges 32 of the active electrodes 24, 26, 28, 30 are separated from eachanother by a small but significant distance, d. Electrically isolatedand thermally conductive metal sections 34 are provided near the outsideedges 36 of the active electrodes 24, 26, 28, 30.

The treatment tip 14 includes temperature sensors 38, such asthermistors or thermocouples, that are constructed to sense thetemperature at each of the four corners of the treatment electrode 20.The measured temperature reflects the temperature of the treated tissueand may be used as feedback in a control loop controlling energydelivery and/or cooling of the skin surface. The handpiece 12 ortreatment tip 14 may also include pressure sensors (not shown) fordetecting physical contact between the treatment electrode 20 and theskin surface of the patient.

The active electrodes 24, 26, 28, 30 are physically carried on a side ofthe substrate 22 that does not contact the skin surface and is thereforeseparated by the substrate 22 from the skin surface. In one embodiment,the substrate 22 of the treatment electrode 20 may comprise a thinflexible base polymer film carrying the active electrodes 24, 26, 28, 30and thin conductive (e.g., copper) traces or leads on the substrate 22that electrically couple the active electrodes 24, 26, 28, 30 withcontact pads inside the treatment tip 14. The base polymer film ofsubstrate 22 may be, for example, polyimide or another material with arelatively high electrical resistivity and a relatively high thermalconductivity. The conductive leads may contain copper or anothermaterial characterized by a relatively high electrical conductivity.

The treatment tip 14 may include a different number of active electrodesthan the total of four active electrodes 24, 26, 28, 30. The activeelectrodes 24, 26, 28, 30 can be sized such that a maximum power toenergize any single electrode is approximately equal to the maximumpower output of the high frequency generator 42. In this example, themaximum power to energize any two of the active electrodes 24, 26, 28,30 would exceed the maximum power output of the high frequency generator42. According to an alternative embodiment, the active electrodes 24,26, 28, 30 may be made smaller in size, and groups of the activeelectrodes 24, 26, 28, 30 may be sequentially powered, with the powerrequired to energize any single group being slightly less than themaximum output power of the generator 42.

In various embodiments, each of the active electrodes 24, 26, 28, 30 mayhave a surface area greater than about 1 cm² and, in particular, each ofthe active electrodes 24, 26, 28, 30 may have a surface area in therange of about 1 cm² to about 20 cm². In specific embodiments, each ofthe active electrodes 24, 26, 28, 30 may have a surface area of about 1cm², about 1.5 cm², about 3 cm², about 5 cm², about 7 cm², about 10 cm²,about 15 cm², or about 20 cm².

The active electrodes 24, 26, 28, 30 are electrically coupled by a setof insulated and shielded conductors 40 that extend exteriorly of thehandpiece 12 to a generator 42 at the console 16. A multiplexer 44 isused to select which of the active electrodes 24, 26, 28, 30 iselectrically coupled with the generator 42 at any instant in time. Thegenerator 42 is configured to generate the electromagnetic energy usedin the treatment to impart a therapeutic effect to heat target tissuebeneath the patient's skin surface. The generator 42, which has the formof a high frequency power supply, is equipped with an electrical circuitoperative to generate high frequency electrical current, typically inthe radio-frequency (RF) band of the electromagnetic spectrum. Theoperating frequency of generator 42 may be in the range of severalhundred kHz to about twenty (20) MHz. In one embodiment, the generator42 is a 400 watt, 6.78 MHz high frequency generator. The electricalcircuit in the generator 42 converts a line alternating current voltageinto drive signals for the treatment electrode 20. The drive signalshave an energy content and a duty cycle appropriate for the amount ofpower and the mode of operation that have been selected by theclinician, as understood by a person having ordinary skill in the art.

The system controller 18 may represent practically any computer,computer system, or programmable device recognized by a person havingordinary skill in the art and capable of carrying out the functionsdescribed herein, as will be understood by those of ordinary skill inthe art. System controller 18 typically includes at least one processor23 coupled to a memory 25. Processor 23 may represent one or moreprocessors (e.g., microprocessors), and memory 25 may represent therandom access memory (RAM) devices comprising the main storage of systemcontroller 18, as well as any supplemental levels of memory, e.g., cachememories, non-volatile or backup memories (e.g. programmable or flashmemories), read-only memories, etc. In addition, memory 25 may beconsidered to include memory storage physically located elsewhere insystem controller 18, e.g., any cache memory in a processor 23, as wellas any storage capacity used as a virtual memory, e.g., as stored on amass storage device 27 or another computer (not shown) coupled to systemcontroller 18 via a network.

System controller 18 also typically receives a number of inputs andoutputs for communicating information externally. For interface with auser or operator, system controller 18 typically includes one or moreuser input devices (e.g., a keyboard, a mouse, a trackball, a joystick,a touchpad, a keypad, a stylus, and/or a microphone, among others) inthe form of a user interface 29. System controller 18 may also include adisplay 31 (e.g., a CRT monitor or an LCD display panel, among others).

System controller 18 operates under the control of an operating system33, and executes or otherwise relies upon various computer softwareapplications, components, programs, objects, modules, data structures,etc. In general, the routines executed by the system controller 18 tooperate the treatment system 10, whether implemented as part of anoperating system or a specific application, component, program, object,module or sequence of instructions will be referred to herein as“computer program code”. The computer program code typically comprisesone or more instructions that are resident at various times in variousmemory and storage devices in a computer, and that, when read andexecuted by one or more processors in a computer, causes that computerto perform the steps necessary to execute steps or elements embodyingthe various aspects of the invention.

The system controller 18 includes digital and/or analog circuitry thatinterfaces the processor 23 with the generator 42 for regulating thepower delivered from the generator 42 to the treatment electrode 20 andwith the multiplexer 44 for determining which of the active electrodes46, 48, 50, 52 is coupled with the generator. Generator software 35resides as an application in the memory 25 and is executed by theprocessor 23 in order to issue commands that control the operation ofthe generator 42. The system controller 18 includes digital and/oranalog circuitry that interfaces the processor 23 with a cryogen supply58, such as a pre-filled canister containing pressurized cryogen, and acontrol valve for regulating the cryogen delivered to the treatmentelectrode 20. Cryogen software 37 resides as an application in thememory 25 and is executed by the processor 23 in order to issue commandsthat control the operation of the cryogen supply 58 and a control valve.

The user interface 29 may be used to deliver instructions to the systemcontroller 18 to adjust the generator 42 and multiplexer 44 and toestablish an arbitrary treatment setting based upon operator input atthe handpiece 12. The memory 25 may be used to store the parameters ofthe power profile shown in FIG. 4. System controller 18 may alsocommunicate, for example, with a nonvolatile memory (not shown) carriedby the handpiece 12 or with a nonvolatile memory (not shown) carried bythe treatment tip 14.

The multiplexer 44 includes switches 46, 48, 50, 52, such as relays oranother type of switching device or circuit, that are adapted to beswitched between closed and open conditions by the system controller 18.In the closed condition, a signal or current path is established thatelectrically connects one of the terminals of the high frequencygenerator 42 and a respective one of the active electrodes 24, 26, 28,30. In the open condition, the respective one of the active electrodes24, 26, 28, 30 is disconnected from the high frequency generator 42. Themultiplexer 44 may be integrated into the system controller 18,integrated into the generator 42, integrated into the treatment tip 14,or may constitute a separate circuit element controlled by either thesystem controller 18 or generator 42. The multiplexer 44 permits theactive electrodes 24, 26, 28, 30 to be individually energized by thesystem controller 18 in the closed circuit with the generator 42.

During a non-ablative and non-invasive tissue treatment, a portion ofthe treatment electrode 20 has a direct contacting relationship with theskin surface of the patient. In the representative arrangement, thesubstrate 22 is arranged between the active electrodes 24, 26, 28, 30and the skin surface so that a portion of the substrate 22 directlycontacts the skin surface. Electromagnetic energy is transmitted in atranscutaneous manner from each of the active electrodes 24, 26, 28, 30through the thickness of the portion of substrate 22 to the tissue bycapacitive coupling with the tissue of the patient.

An activation button 54, which is accessible to the operator from theexterior of the handpiece 12, is configured to be actuated to close aswitch in a normally open circuit with the generator 42. The closedcircuit energizes the treatment electrode 20. Actuation of theactivation button 54 triggers delivery of the high frequency energy overa short timed delivery cycle from the treatment electrode 20 to thetarget tissue. After a fixed amount of time has elapsed, the delivery ofhigh frequency energy from the treatment electrode 20 to the tissue atthe treatment site is discontinued. The handpiece 12 is manipulated toposition the treatment tip 14 near a different treatment site on theskin surface and another cycle of high frequency energy is delivered tothe patient's tissue. This process is repeated for an arbitrary numberof treatment sites.

High frequency electrical current flowing between the treatmentelectrode 20 and the patient is concentrated at the skin surface and theunderlying tissue across the contacting surface area of the treatmentelectrode 20. Capacitive coupling of the high frequency electromagneticenergy relies on energy transfer from each of the active electrodes 24,26, 28, 30 through the dielectric material of the substrate 22 to createan electric field across the surface area where the treatment electrode20 contacts the patient's body. The time-varying electric field induceselectrical currents within the surrounding tissue beneath the skinsurface.

Because of the natural resistance of tissue to electrical current flow,volumetric heating results within the tissue. The volumetric heatingdelivers a therapeutic effect to the tissue at the treatment site. Forexample, heating to a temperature effective to contract collagencontaining tissue at the treatment site, which will result in tissuetightening or another aesthetic effect that improves the patient'sappearance. The heating depth in the tissue is based upon the size andgeometry of the treatment electrode 20 and, contingent upon theselection and configuration of the treatment tip 14, can be controlledto extend from a few hundred microns beneath the skin surface to severalmillimeters.

A non-therapeutic passive return electrode 56 is used to electricallycouple the patient with the generator 42. During patient treatment, thehigh frequency current flows from the treatment electrode 20 through thetreated tissue and the intervening bulk of the patient to the returnelectrode 56 and then to the generator 42 through conductors 40 inside areturn cable to define a closed circuit or current path. The returnelectrode 56 is physically attached by, for example, an adhesive bond toa site on the body surface of the patient, such as the patient's back.

The surface area of the return electrode 56 in contact with the patientis relatively large in comparison with the surface area of the treatmentelectrode 20. Consequently, at the tissue adjacent to the returnelectrode 56, the current density flowing from the patient to the returnelectrode 56 is relatively low in comparison with the current densityflowing from the treatment electrode 20 to the patient at the treatmentsite remote from the return electrode 56. Because negligible heating isproduced at its attachment site to the patient, a non-therapeutic effectis created in the tissue adjacent to the return electrode 56.

Although the treatment electrode 20 and the return electrode 56 arerepresentatively configured for the delivery of monopolar high frequencyenergy, the treatment electrode 20 may be configured to deliver bipolarhigh frequency energy. The modifications to the treatment apparatus 10required to deliver bipolar high frequency energy are familiar to aperson having ordinary skill in the art. For example, the returnelectrode 56 may be eliminated from the treatment apparatus 10 and abipolar type of treatment electrode substituted for the monopolartreatment electrode 20.

A control valve (not shown) in either the treatment tip 14 or handpiece12 is used to deliver a cryogen spray to the back side of the treatmentelectrode 20 for controlling the temperature of the treatment electrode20. One purpose of the cryogen spray is to pre-cool the patient'sepidermis, before powering the treatment electrode 20, by heat transferbetween the treatment electrode 20 and the skin surface. The coolingcreates a reverse thermal gradient in the tissue such that thetemperature of the tissue at and near the skin surface is cooler thanthe temperature of the tissue deeper within the epidermis or dermis. Asa result, the high frequency energy delivered to the tissue fails toheat all or a portion of the patient's epidermis to a temperaturesufficient to cause significant epidermal thermal damage. Depths oftissue that are not significantly cooled by pre-cooling will warm up totherapeutic temperatures, which cause a desired therapeutic effect. Theamount and/or duration of pre-cooling may be used to select theprotected depth of untreated tissue. The cryogen delivered by thecontrol valve in the treatment tip 14 may also be used to cool portionsof the tissue during and/or after heating by the high frequency energytransferred from the treatment electrode 20. Post-cooling may prevent orreduce heat delivered deeper into the tissue from conducting upward andheating shallower tissue regions, such as the epidermis, to temperatureswhich could thermally damage shallower tissue regions even thoughexternal energy delivery to the targeted tissue has ceased.

Various duty cycles of cooling and heating that rely on cooling and highfrequency energy transfer from the treatment electrode 20 are utilizedcontingent upon the type of treatment and the desired type oftherapeutic effect. The cooling and heating duty cycles may becontrolled and coordinated by operation of the system controller 18.Suitable cryogens include low boiling point fluids, but are not limitedto, R134a (1,1,1,2-Tetrafluoroethane) refrigerant, liquid nitrogen, andR152a refrigerant (1,1-Difluoroethane). Heat can be extracted from thetreatment electrode 20 by virtue of evaporative cooling of the lowboiling point fluid, which cools the treatment electrode 20. Inalternative embodiments, the patient's skin and/or the treatmentelectrode 20 may be cooled in a different manner, such as with athermoelectric or Peltier device, a closed-loop fluid cooling, or aZimmer cooler that is configured to deliver a forced stream of cold aironto the skin surface.

With reference to FIG. 4, the power supplied from the generator 42 toeach of the active electrodes 24, 26, 28, 30 may be modulated by thesystem controller 18 to have a characteristic profile of energy deliveryas a function of treatment time. Specifically, the profile may contain aplurality of different power levels 60-69 and the system controller 18may cause the generator 42, which has circuitry known to a person havingordinary skill in the art for adjusting the output power, tosequentially step from one power level to the next power level as timeevolves during a treatment repetition with each of the active electrodes24, 26, 28, 30. A treatment repetition is constituted by the sequentialapplication of power using the power profile of FIG. 4 to one of theactive electrodes 24, 26, 28, 30 while maintaining the contactingrelationship with the skin surface 82 and the rest of the activeelectrodes 24, 26, 28, 30 in a non-energized status. In turn, each ofthe active electrodes 24, 26, 28, 30 is energized using the profile.

The total time, t, for each treatment repetition using any one of theactive electrodes 24, 26, 28, 30 is divided into a number, n, ofdiscrete power levels 60-69. In the representative embodiment of FIG. 4,the total treatment time, t, for a single treatment repetition isdivided into ten (10) intervals and each of the intervals ischaracterized by one of the power levels 60-69 associated with it.However, a different number of time intervals and power levels 60-69 maybe selected in accordance with the treatment protocol. The duration ofeach time interval is established as a fraction given by the total time,t, divided by the number, n, of power levels 60-69. In therepresentative embodiment of FIG. 4, the ten (10) time intervals are ofequal duration, although the embodiments of the invention are not solimited to being isochronal. For example, the length of the timeintervals may increase with increasing time or, alternatively, maydecrease with increasing time.

In the representative embodiment, the applied power differs at each ofthe power levels 60-69. Generally, a different power need only beapplied for at least two of the power levels 60-69. In yet anotherembodiment, the same power may be applied at two or more, but not all,of the power levels 60-69. For example, the power applied at the initialand second power levels 60 may be the same, and the power applied ateach successive power level 60-69 thereafter may decrease in aprogressive manner. As another example, the same power may be appliedduring three power levels, for example power levels 62-64, between theinitial power level 60 and final power level 69, and the power appliedat the power levels 60, 61 before and the power levels 65-69 after thesethree power levels 62-64 may progressively decrease.

Over the duration of each of the power levels 60-69, the power at thatparticular power level 60-69 is maintained constant at a percentage ofthe target power in the representative embodiment. The transitionbetween each adjacent pair of power levels 60-69 is abrupt anddiscontinuous as the generator 42 is instructed by the system controller18 to reduce the power. The power levels 60-69 are applied during asingle treatment repetition and without moving the treatment electrode20 so that electromagnetic energy is sequentially delivered from each ofthe active electrodes 24, 26, 28, 30 with the treatment electrode 20stationary and without any quiescent time periods to a region of tissueat each of the power levels 60-69. As a result, each tissue region thatis treated received the electromagnetic energy at a series of powerlevels 60-69 that progressively decrease with increasing treatment time.

The total time, t, for a single treatment repetition of all power levels60-69 according to FIG. 4 for any one of the active electrodes 24, 26,28, 30 may range from one (1) to three (3) seconds. As an example, ifthe total time, t, is one second, the number of time intervals is ten,and the time intervals are of equal duration, then the duration of eachtime interval is 100 milliseconds. After the lapse of the total time, t,and completion of all of the power levels 60, the power is reduced tozero (0) in anticipation of energizing the next active electrode of thetreatment electrode 20 to perform the next treatment repetition or,alternatively, in anticipation of lifting the treatment tip 14 to moveto the next treatment location for another series of treatmentrepetitions.

The power supplied from the generator 42 to any one of the activeelectrodes 24, 26, 28, 30 during a treatment repetition is bounded in arange bounded by upper and lower limits. The upper and lower limits forthis range are denoted, respectively, by a maximum setting for theapplied power over the time, t, for a single repetition and a minimumsetting for the applied power over the time, t, for a single repetition.In the representative embodiment of FIG. 4, the maximum setting targetedfor the power is at least 120% (at least 20% above a nominal powersetting) at the initial power level 60 and the minimum setting targetedfor the power is at least 80% (at least 20% below the same nominal powersetting) at the final power level 69. A typical nominal power settingmay be on the order of 200 joules per second and, in alternativeembodiments, may be selected as any value less than 400 joules persecond effective to achieve a therapeutic effect.

In the representative embodiment depicted in FIG. 4, the maximum poweris supplied as the initial power level 60 during the initial timeinterval and the minimum power is supplied as the final power level 69during the final time interval. This cascading approach results in thepower of the electromagnetic energy delivered at each of the differingpower levels 60-69 to decrease with increasing treatment time, t. In oneembodiment, the power at each successive power level 60-69 withadvancing time is less than the power at the immediately previous powerlevel 60-69 so that the treatment protocol for each of the activeelectrodes 24, 26, 28, 30 has a descending profile over the total time,t. However, the minimum and maximum powers may be supplied at differenttime intervals between the initial and final time intervals. Forexample, the maximum power may be applied as the power level 65 duringthe sixth time interval. As another example, the minimum power may beapplied at the power level 69 for the final time interval and also atthe power level 68 for the next to last time interval.

The system controller 18 implements the various parameters of the powerprofile in FIG. 4 using control signals sent to the generator 42 whenpower is applied to each of the active electrodes 24, 26, 28, 30according to the switching by the multiplexer 44. The memory 25 of thesystem controller 18 stores the various parameters for the powerprofile. The application of the stepped power profile of FIG. 4 promotesthe ability to deliver electromagnetic energy across a larger surfacearea on the skin surface by decreasing the pain sensitivity of thepatient. The power profile of FIG. 4 permits an increase in the totalpower delivered by each of the active electrodes 24, 26, 28, 30 to thepatient's tissue. The power profile is implemented in an open loopcontrol system because there is no feedback provided for control.Instead, the power profile is implemented on a timed basis at the systemcontroller 18.

The use of the power profile of FIG. 4 may be applied to treatmentelectrodes of relatively large area and/or treatment electrodes thathave only a single active electrode, instead of the segmented treatmentelectrode 20 that has multiple active electrodes 24, 26, 28, 30. Forexample, the power profile of FIG. 4 may be applied in conjunction withthe treatment electrode 20 a (FIG. 5) that has a single region composedof electrical conductor defining one active electrode so that eachrepetition normally includes only a single contact with the skinsurface, energy delivery, and lift to move for the next treatmentrepetition.

In use to perform a treatment procedure and with reference to FIGS. 1-4,the physician selects a type of treatment tip 14 based on the procedureto be performed and the size of the surface area on the patient to betreated, as well as the depth of cooling and heating desired for thetreatment procedure. The procedure protocol may include a combination ofpulse count, pulse duration, as well as the power levels and heatingprofile of FIG. 4. After choosing the treatment tip 14 and attaching itto the handpiece 12, the physician marks the intended treatment area onthe patient with a grid of removable markings that are easily wiped awaypost-procedure. Each discrete square in the grid correspondsapproximately to the size of the portion of the treatment electrode 20that is placed in direct contact with the skin surface. The markingsoperate as a placement guide on the patient's skin surface for thetreatment procedure. The return electrode 56 is attached to the patientto supply the current path for the high frequency current back to thegenerator 42.

After the optional application of a conductive fluid, each square withinthe grid is sequentially treated with high frequency energy deliveredfrom the treatment electrode 20. Specifically, at each grid square, thephysician lands the portion of treatment electrode 20 directly againstthe patient's skin and actuates the activation button 54 on thehandpiece 12, which causes the system controller 18 to direct a meteredspray of a cryogen to the backside of the active electrodes 24, 26, 28,30 for pre-cooling the patient's tissue adjacent to the treatmentelectrode 20 by heat transfer through the treatment electrode 20. Acontrol valve regulates the delivery of cryogen, which cools andprotects the skin's superficial layers proximate to the skin surface.Cooling the epidermis limits the temperature to lessen the likelihood ofthermal damage to at least the outer layers of the epidermis. Depths oftissue that are not significantly cooled by pre-cooling will be heatedto therapeutic temperatures resulting in the desired therapeutic effect.The amount or duration of pre-cooling may be used to select theprotected depth of untreated tissue. Lengthier durations of pre-coolingproduce a deeper protected zone in the tissue, while the conversesituation occurs for shorter periods of pre-cooling.

After a short interval to permit the tissue to be cooled to a targetedpre-cool temperature, system controller 18 actuates switch 46 ofmultiplexer 44 to close the current path between electrode 24 andgenerator 42. The other switches 48, 50, 52 remain in an open conditionso that the circuits to electrodes 26, 28, 30 are open and unpowered.Actuating switch 46 causes the electrode 24 to be energized by the highfrequency generator 42 to deliver high frequency energy over a firsttime period to treat the first region of the tissue beneath theelectrode 24 and around its edges 32, 36. The active electrode 24transmits high frequency energy to the skin according to the powerprofile with the power levels 60-69 depicted in FIG. 4 while serving asa skin contact cooling membrane for the cryogen. If needed, additionalamounts of coolant may be delivered to sustain a suitable coolingprofile for removing heat from the patient's tissue during, before, orafter energization of any or all of the active electrodes 24, 26, 28,30.

The system controller 18 monitors a combination of inputs, such astemperatures, power levels and delivery duration, to precisely andsafely control the high frequency energy and cooling delivery to eachtreatment site in the grid. During treatment using the energized activeelectrode 24, the handpiece 12 and system controller 18 cooperate toprocess information received from the treatment tip 14 about skintemperature, skin contact, treatment force, and/or pressure against theskin; cooling system function; and other types of relevant data in orderto generate the proper high frequency signal at the generator 42 andappropriate cooling.

At the conclusion of the first repetition with electrode 24, switch 46of multiplexer 44 is opened by system controller 18 to open the currentpath from the generator 42 to electrode 24. The system controller 18actuates switch 48 to a closed position to close the circuit with thegenerator 42 and a second tissue region proximate to electrode 26 isthen treated with high frequency energy. Switches 46, 50 and 52 of themultiplexer 44 remain open so that active electrodes 24, 28, 30 areunpowered. The power is delivered to the active electrode 26 and to thetreated tissue according to the power profile depicted in FIG. 4.Because the second tissue region has already been pre-cooled, highfrequency energy may be delivered to the second tissue region over asecond time period with a minimal time delay after the end of the firsttime period. While the second tissue region is being treated over thesecond time period, the first region receives a post-cooling treatment.A third tissue region proximate to electrode 28 is pre-cooled inanticipation of subsequent treatment with high frequency energy at theconclusion of the second time period. In a similar manner, themultiplexer 44 is used to serially close the current path between arespective one of the active electrodes 28, 30 of the treatmentelectrode 20 and the generator 42 to treat the third tissue regionproximate to electrode 28 and a fourth tissue region proximate toelectrode 30. The power is delivered to these active electrodes 28, 30and to the treated tissue according to the power profile depicted inFIG. 4.

As a result of the switching on and off of the electrodes, the activeelectrodes 24, 26, 28, 30 are sequentially energized by generator 42 todeliver high frequency energy to different regions of the patient'stissue beneath the skin surface while the treatment electrode 20 isproximate but external to the skin surface. Only one of the activeelectrodes 24, 26, 28, 30 is energized with high frequency energy at anyinstant in time, although multiple electrodes or groups of electrodesmay be energized at any one time.

The coolant may also be used to cool portions of the tissue regionsafter heating by the transferred high frequency energy from activeelectrodes 24, 26, 28, 30. Post-cooling may prevent or reduce heatdelivered deeper into the tissue from conducting outward toward the skinsurface and heating shallower tissue regions, such as the epidermis, totemperatures which could burn the epidermis even though the externalenergy delivery to the targeted tissue has ceased.

After energy delivery is completed from all of the active electrodes 24,26, 28, 30 and any post-cooling is completed, the handpiece 12 ismaneuvered to lift the portion of the treatment electrode 20 from theskin surface. The handpiece 12 and treatment tip 14 are moved amongsubsequent treatment locations in the grid and energy is delivered is asimilar manner for treating large regions on the patient, such as thepatient's face. Power is delivered to each of the active electrodes 24,26, 28, 30 and to the treated tissue at each of the subsequent treatmentlocations according to the power levels 60-69 of the power profiledepicted in FIG. 4. Multiple passes over the entire grid of thetreatment zone, separated in time by a quiescent period of a fewminutes, may be used to enhance the treatment, as understood by personsskilled in the art. Multiple treatments, which are separated temporallyby a lengthier healing period, may be needed for a treatment thatsupplies the desired cosmetic effect.

With reference to FIG. 5 and in accordance with an embodiment of theinvention, an electrically-insulating sleeve 70 is applied to theforward end of the treatment tip 14. In the representative embodiment,the treatment tip 14 is equipped with a single treatment electrode 20 ahaving a single active electrode 24 a composed of electrical conductoron substrate 22, rather than populated with the plurality of activeelectrodes 24, 26, 28, 30 (FIG. 3). The sleeve 70 includes a skirt 72that wraps about the treatment tip 14 and a tip frame 74 that encirclesthe active electrode 24 a of the treatment electrode 20 a. The skirt 72secures the sleeve 70 to the treatment tip 14 and intersects the tipframe 74 at a corner extending circumferentially about an outer edge 75of the frame 74. The skirt 72 and tip frame 74 have a unitary structureor, alternatively, may have an integral construction in which multiplecomponents are joined together.

The sleeve 70 is preferably composed of a solid electrically-insulatingmaterial or a dielectric material that is a poor conductor ofelectricity, but an efficient supporter of electrostatic fieldsestablished by the alternating high frequency electric field from theactive electrode 24 a. In one embodiment, the sleeve 70 may be composedof a sheet of a thin flexible base polymer film such as polyimide oranother material characterized by a relatively high electricalresistivity and a relatively high thermal conductivity. In anotherembodiment, the sleeve 70 may be composed of a thin sheet of a materialidentical to the material from which the substrate 22 of the treatmentelectrode 20 a is composed. In various embodiments, the sleeve 70 mayhave a thickness within the range of 1 millimeter to 2 millimeters.

The tip frame 74 extends inwardly from the outer edge 75 with a width,w₁, that is sufficient to overlap a small gap 76 that exists between theouter side edge of the treatment electrode 20 a and the inner side edgeof the housing 15 of the treatment tip 14. The tip frame 74 includes aplurality of inside edges 80 that intersect at approximately rightangles and a plurality of inside corners 78 defined by the inside edges80. The inside edges 80 delineate an inner perimeter that extends aboutthe entire circumference of the active electrode 24 a of the treatmenttip 14 and that defines an aperture or opening 81. In the representativeembodiment, the width, w₁, of the tip frame 74 is uniform about thecircumference. The opening 81, which is rectangular or square with rightangle inside corners 78 in the representative embodiment, partiallyexposes the active electrode 24 a. Varying the width, w₁, of the tipframe 74 changes the exposed area of the active electrode 24 a.Preferably, the majority of the surface area of conductor composing theactive electrode 24 a is exposed by the opening 81. The outer peripheraledge 21 of the conductor constituting the active electrode 24 a and gap76 are overlapped and covered by the tip frame 74.

The tip frame 74 of the sleeve 70 is interposed as a thin sheet of adielectric material between the treatment tip 14 and the surface 82 ofthe skin 83 during a treatment repetition. As apparent in FIG. 6, thetip frame 74 is pressed against the skin surface 82 and operates as aspacer or standoff that separates a portion of the active electrode 24 aof treatment electrode 20 a from the skin surface to define a shallowcavity 86. Peripherally inside the inside edges 80 of the tip frame 74,the front surface 84 of the dielectric substrate 22 of the treatmentelectrode 20 a has a contacting relationship with the skin surface 82.However, the portion of the skin surface 82 inside the inside edges 80of the tip frame 74 is free to relax outwardly within the shallow cavity86. As a result, the skin surface 82 contacting the front surface 84 ofthe treatment electrode 20 a develops a curvature characterized by arelatively large radius of curvature, R. The resulting appearance of theskin surface 82 is more spherical than planar.

With reference to FIG. 7 and in accordance with an alternativeembodiment of the invention, a sleeve 90 includes a tip frame 92 with aset of inside corners 94 that are modified to have a radius of curvaturerather than right angle junctions, but is otherwise similar to sleeve 70(FIGS. 5, 7).

With reference to FIG. 8 and in accordance with another alternativeembodiment of the invention, a sleeve 96 includes a frame 98characterized by an increased width, w₂, in comparison with the tipframe 74 of sleeve 70 (FIGS. 5, 7), but is otherwise similar to sleeve70.

With reference to FIG. 9 and in accordance with yet another alternativeembodiment of the invention, a sleeve 100 includes a frame 102characterized by an increased width, w₃, in comparison with the width offrame 98 of sleeve 96 (FIG. 8), but is otherwise similar to sleeve 96(FIG. 8).

The thickness of any of the frames 74, 92, 98, 102 may be selected tooptimize the beneficial effects, as described below. Among otherfactors, increasing the thickness will operate to increase the radius ofcurvature, R, of the skin surface 82.

The sleeves 70, 90, 96, 100, which may be used in conjunction withtreatment electrode 20 a, treatment electrode 20 (FIGS. 1-3), or withany other similar type of treatment electrode, are believed to beeffective in reducing the edge effect observed during treatmentprocedures. Specifically, the sleeves 70, 90, 96, 100 are believed toalleviate or mitigate overheating from the maximized energy density nearthe peripheral edge of the treatment electrode 20 a. Consequently, theoccurrence of hot spot thermal zones near the peripheral edges of thetreatment electrode 20 a is reduced. This permits higher treatmentlevels with an increased average energy density, in comparison with theabsence of one of the sleeves 70, 90, 96, 100, for the high frequencyenergy delivered during the treatment procedure.

With reference to FIG. 10 and in accordance with an embodiment of theinvention, a tip frame 120 is directly applied or mounted to the exposedsurface of the treatment electrode 20 a at the forward end of thetreatment tip 14. The tip frame 120 omits the skirt 72 found in sleeves70, 90, 96, 100. However, similar to the tip frame 74 found in sleeves70, 90, 96, 100, the tip frame 120 encircles the active electrode 24 aand includes the aperture or opening 81 defined by inner edges 80. Thetip frame 120 may be adhesively bonded to the substrate 22 of thetreatment electrode 20 a or may be integrally formed with the substrate22 of treatment electrode 20 a. The tip frame 120 may be composed of thesame solid electrically-insulating material or dielectric material asthe sleeves 70, 90, 96, 100.

The tip frame 120 extends inwardly from the outer edge 75 with a width,w₁, that is sufficient to overlap the gap 76 that exists between theouter side edge of the treatment electrode 20 a and the inner side edgeof the housing 15 of the treatment tip 14. The inside corners 78 of thetip frame 120 are defined by the inside edges 80 that intersect atapproximately right angles. However, the inside edges 80 may be modifiedas shown in FIGS. 7 and 9 and the width of the tip frame 120 may bemodified as shown in FIGS. 8 and 9. The inside edges 80 define an innerperimeter that extends about the entire circumference of the activeelectrode 24 a of treatment electrode 20 a. In the representativeembodiment, the width, w₁, of the tip frame 120 is circumferentiallyuniform. The opening 81, which is rectangular or square with right angleinside corners 78 in the representative embodiment, partially exposesthe active electrode 24 a. Varying the width, w₁, of the tip frame 120changes the exposed surface area of active electrode 24 a. The tip frame120 is interposed between the substrate 22 of treatment electrode 20 aand the skin surface 82 during a treatment repetition such that thearrangement is similar to that shown in FIG. 6.

With reference to FIGS. 11, 11A, and 12 and in accordance with anembodiment of the invention, a tip frame 130 is directly applied ormounted to the exposed surface of the substrate 22 of treatmentelectrode 20. Similar to tip frame 120 (FIG. 10), tip frame 130 omitsthe skirt 72 found in sleeves 70, 90, 96, 100. The tip frame 130includes a plurality of apertures or openings 132, 134, 136, 138 thatcoincides numerically with the number of active electrodes 24, 26, 28,30. An inner perimeter of each of the openings 132, 134, 136, 138includes a combination of linear and curved inner edges that arearranged to provide an aperture shape that matches the shape of thecorresponding one of the active electrodes 24, 26, 28, 30. The tip frame130 may be adhesively bonded to the substrate 22 of the treatmentelectrode 20 or may be integrally formed with the substrate 22 of thetreatment electrode 20.

The tip frame 130 is preferably composed of a solidelectrically-insulating material or a dielectric material that is a poorconductor of electricity, but an efficient supporter of electrostaticfields established by an alternating electric field emitted by theactive electrodes 24, 26, 28, 30 of treatment electrode 20 during energydelivery. In one embodiment, the tip frame 130 may be composed of a thinsheet of a flexible base polymer film such as polyimide or anothermaterial characterized by a relatively high electrical resistivity and arelatively high thermal conductivity. In another embodiment, the tipframe 130 and the substrate 22 of the treatment electrode 20 may becomposed of the same material.

As apparent in FIG. 12, the tip frame 130 is pressed against the skinsurface 82 and operates as a spacer or standoff that separates thesubstrate 22 of the treatment electrode 20 from the skin surface.Peripherally inside the inside edges surrounding each of the openings132, 134, 136, 138 in the tip frame 130, a front surface 140 of each ofthe substrate overlying each of the active electrodes 24, 26, 28, 30 hasa contacting relationship with the skin surface 82. However, the portionof the skin surface 82 inside the inside edges surrounding the openings132, 134, 136, 138 is free to relax outwardly such that the surface 82of the skin 83 develops a curvature characterized by a radius ofcurvature, R.

The housing 15 of the treatment tip 14 includes a rim 144 that encirclesthe forward end of the treatment electrode 20. An outer peripheral edge146 of the tip frame 130 is arranged laterally inside of the rim 144with a circumscribed relationship relative to the rim 144. The tip frame130 is slightly recessed axially relative to the rim 144 such that thehousing 15 proximate to the rim 144 covers the outer peripheral edge146. In one embodiment, the front surface 148 of the tip frame 130 isflush (or co-planar) with the rim 144. This spatial relationship ensuresthat the outer peripheral edge 146 of the tip frame 130 cannot contactthe skin surface 82 when the tip frame 130 is pressed against the skinsurface 82. For example, the process fabricating the tip frame 130 mayprovide an outer peripheral edge 146 that is sharp or rough, which mayresult in patient discomfort, and the outer peripheral edge 146 of thetip frame 130 shields the skin surface 82 from the sharp or rough outerperipheral edge 146.

References herein to terms such as “vertical”, “horizontal”, etc. aremade by way of example, and not by way of limitation, to establish aframe of reference. It is understood that various other frames ofreference may be employed for describing the invention without departingfrom the spirit and scope of the invention. It is also understood thatfeatures of the invention are not necessarily shown to scale in thedrawings. Furthermore, to the extent that the terms “composed of”,“includes”, “having”, “has”, “with”, or variants thereof are used ineither the detailed description or the claims, such terms are intendedto be inclusive and open-ended in a manner similar to the term“comprising”.

It will be understood that when an element is described as being“attached”, “connected”, or “coupled” to another element, it can bedirectly connected or coupled to the other element or interveningelements may be present. In contrast, when an element is described asbeing “directly attached”, “directly connected”, or “directly coupled”to another element, there are no intervening elements present.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

While the invention has been illustrated by a description of variousembodiments and while these embodiments have been described inconsiderable detail, it is not the intention of the applicant torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Thus, the invention in its broader aspects istherefore not limited to the specific details, representative apparatusand method, and illustrative example shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of applicants' general inventive concept.

What is claimed is:
 1. A method of operating a tissue treatmentapparatus to transcutaneously treat tissue located beneath a skinsurface with electromagnetic energy delivered from a treatmentelectrode, the method comprising: contacting a portion of the treatmentelectrode with the skin surface at a first treatment location; anddelivering the electromagnetic energy from the treatment electrodethrough the skin surface to the tissue at the first treatment location,wherein the electromagnetic energy is delivered with a power profilehaving a plurality of differing power levels over a treatment timedivided into a plurality of time intervals each associated with arespective one of the power levels, the differing power levels rangefrom a first power that is at least 20 percent above a nominal power of200 joules per second to a second power that is at least 20 percentbelow the nominal power, and the power profile is implemented withoutfeedback control.
 2. The method of claim 1 wherein a power of theelectromagnetic energy delivered at each of the differing power levelsdecreases with increasing treatment time.
 3. The method of claim 1wherein the treatment electrode includes a plurality of activeelectrodes, and delivering the electromagnetic energy from the treatmentelectrode through the skin surface to the tissue at the differing powerlevels in the first treatment repetition over the treatment timecomprises: delivering the electromagnetic energy from each of the activeelectrodes through the skin surface to the tissue at the differing powerlevels over an iteration of the treatment time while maintaining theportion of the treatment electrode in contact with the skin surface. 4.The method of claim 1 wherein the time intervals are isochronal.
 5. Themethod of claim 1 wherein the portion of the treatment electrode ismaintained stationary relative to the skin surface while delivering theelectromagnetic energy.
 6. The method of claim 1 wherein theelectromagnetic energy is delivered from the treatment electrode whilemaintaining contact between the portion of the treatment electrode andthe skin surface.
 7. The method of claim 1 further comprising: after theelectromagnetic energy is delivered from the treatment electrode throughthe skin surface to the tissue at the first treatment location, liftingthe portion of the treatment electrode from the skin surface; contactingthe portion of the treatment electrode with the skin surface at a secondtreatment location; and delivering the electromagnetic energy from thetreatment electrode through the skin surface to the tissue at the secondtreatment location with the differing power levels over the treatmenttime.
 8. The method of claim 1 wherein the power profile is implementedwith open loop control over the power profile.
 9. The method of claim 1wherein the power profile is implemented on a timed basis.